spa_config.c revision 303975
1/* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 22/* 23 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. 24 * Copyright 2011 Nexenta Systems, Inc. All rights reserved. 25 * Copyright (c) 2011, 2015 by Delphix. All rights reserved. 26 */ 27 28#include <sys/zfs_context.h> 29#include <sys/spa.h> 30#include <sys/fm/fs/zfs.h> 31#include <sys/spa_impl.h> 32#include <sys/nvpair.h> 33#include <sys/uio.h> 34#include <sys/fs/zfs.h> 35#include <sys/vdev_impl.h> 36#include <sys/zfs_ioctl.h> 37#include <sys/utsname.h> 38#include <sys/sunddi.h> 39#include <sys/zfeature.h> 40#ifdef _KERNEL 41#include <sys/kobj.h> 42#include <sys/zone.h> 43#endif 44 45/* 46 * Pool configuration repository. 47 * 48 * Pool configuration is stored as a packed nvlist on the filesystem. By 49 * default, all pools are stored in /etc/zfs/zpool.cache and loaded on boot 50 * (when the ZFS module is loaded). Pools can also have the 'cachefile' 51 * property set that allows them to be stored in an alternate location until 52 * the control of external software. 53 * 54 * For each cache file, we have a single nvlist which holds all the 55 * configuration information. When the module loads, we read this information 56 * from /etc/zfs/zpool.cache and populate the SPA namespace. This namespace is 57 * maintained independently in spa.c. Whenever the namespace is modified, or 58 * the configuration of a pool is changed, we call spa_config_sync(), which 59 * walks through all the active pools and writes the configuration to disk. 60 */ 61 62static uint64_t spa_config_generation = 1; 63 64/* 65 * This can be overridden in userland to preserve an alternate namespace for 66 * userland pools when doing testing. 67 */ 68const char *spa_config_path = ZPOOL_CACHE; 69 70/* 71 * Called when the module is first loaded, this routine loads the configuration 72 * file into the SPA namespace. It does not actually open or load the pools; it 73 * only populates the namespace. 74 */ 75void 76spa_config_load(void) 77{ 78 void *buf = NULL; 79 nvlist_t *nvlist, *child; 80 nvpair_t *nvpair; 81 char *pathname; 82 struct _buf *file; 83 uint64_t fsize; 84 85 /* 86 * Open the configuration file. 87 */ 88 pathname = kmem_alloc(MAXPATHLEN, KM_SLEEP); 89 90 (void) snprintf(pathname, MAXPATHLEN, "%s", spa_config_path); 91 92 file = kobj_open_file(pathname); 93 94 kmem_free(pathname, MAXPATHLEN); 95 96 if (file == (struct _buf *)-1) 97 return; 98 99 if (kobj_get_filesize(file, &fsize) != 0) 100 goto out; 101 102 buf = kmem_alloc(fsize, KM_SLEEP); 103 104 /* 105 * Read the nvlist from the file. 106 */ 107 if (kobj_read_file(file, buf, fsize, 0) < 0) 108 goto out; 109 110 /* 111 * Unpack the nvlist. 112 */ 113 if (nvlist_unpack(buf, fsize, &nvlist, KM_SLEEP) != 0) 114 goto out; 115 116 /* 117 * Iterate over all elements in the nvlist, creating a new spa_t for 118 * each one with the specified configuration. 119 */ 120 mutex_enter(&spa_namespace_lock); 121 nvpair = NULL; 122 while ((nvpair = nvlist_next_nvpair(nvlist, nvpair)) != NULL) { 123 if (nvpair_type(nvpair) != DATA_TYPE_NVLIST) 124 continue; 125 126 child = fnvpair_value_nvlist(nvpair); 127 128 if (spa_lookup(nvpair_name(nvpair)) != NULL) 129 continue; 130 (void) spa_add(nvpair_name(nvpair), child, NULL); 131 } 132 mutex_exit(&spa_namespace_lock); 133 134 nvlist_free(nvlist); 135 136out: 137 if (buf != NULL) 138 kmem_free(buf, fsize); 139 140 kobj_close_file(file); 141} 142 143static void 144spa_config_clean(nvlist_t *nvl) 145{ 146 nvlist_t **child; 147 nvlist_t *nvroot = NULL; 148 uint_t c, children; 149 150 if (nvlist_lookup_nvlist_array(nvl, ZPOOL_CONFIG_CHILDREN, &child, 151 &children) == 0) { 152 for (c = 0; c < children; c++) 153 spa_config_clean(child[c]); 154 } 155 156 if (nvlist_lookup_nvlist(nvl, ZPOOL_CONFIG_VDEV_TREE, &nvroot) == 0) 157 spa_config_clean(nvroot); 158 159 nvlist_remove(nvl, ZPOOL_CONFIG_VDEV_STATS, DATA_TYPE_UINT64_ARRAY); 160 nvlist_remove(nvl, ZPOOL_CONFIG_SCAN_STATS, DATA_TYPE_UINT64_ARRAY); 161} 162 163static int 164spa_config_write(spa_config_dirent_t *dp, nvlist_t *nvl) 165{ 166 size_t buflen; 167 char *buf; 168 vnode_t *vp; 169 int oflags = FWRITE | FTRUNC | FCREAT | FOFFMAX; 170 char *temp; 171 int err; 172 173 /* 174 * If the nvlist is empty (NULL), then remove the old cachefile. 175 */ 176 if (nvl == NULL) { 177 err = vn_remove(dp->scd_path, UIO_SYSSPACE, RMFILE); 178 return (err); 179 } 180 181 /* 182 * Pack the configuration into a buffer. 183 */ 184 buf = fnvlist_pack(nvl, &buflen); 185 temp = kmem_zalloc(MAXPATHLEN, KM_SLEEP); 186 187 /* 188 * Write the configuration to disk. We need to do the traditional 189 * 'write to temporary file, sync, move over original' to make sure we 190 * always have a consistent view of the data. 191 */ 192 (void) snprintf(temp, MAXPATHLEN, "%s.tmp", dp->scd_path); 193 194 err = vn_open(temp, UIO_SYSSPACE, oflags, 0644, &vp, CRCREAT, 0); 195 if (err == 0) { 196 err = vn_rdwr(UIO_WRITE, vp, buf, buflen, 0, UIO_SYSSPACE, 197 0, RLIM64_INFINITY, kcred, NULL); 198 if (err == 0) 199 err = VOP_FSYNC(vp, FSYNC, kcred, NULL); 200 if (err == 0) 201 err = vn_rename(temp, dp->scd_path, UIO_SYSSPACE); 202 (void) VOP_CLOSE(vp, oflags, 1, 0, kcred, NULL); 203 } 204 205 (void) vn_remove(temp, UIO_SYSSPACE, RMFILE); 206 207 fnvlist_pack_free(buf, buflen); 208 kmem_free(temp, MAXPATHLEN); 209 return (err); 210} 211 212/* 213 * Synchronize pool configuration to disk. This must be called with the 214 * namespace lock held. Synchronizing the pool cache is typically done after 215 * the configuration has been synced to the MOS. This exposes a window where 216 * the MOS config will have been updated but the cache file has not. If 217 * the system were to crash at that instant then the cached config may not 218 * contain the correct information to open the pool and an explicity import 219 * would be required. 220 */ 221void 222spa_config_sync(spa_t *target, boolean_t removing, boolean_t postsysevent) 223{ 224 spa_config_dirent_t *dp, *tdp; 225 nvlist_t *nvl; 226 boolean_t ccw_failure; 227 int error; 228 229 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 230 231 if (rootdir == NULL || !(spa_mode_global & FWRITE)) 232 return; 233 234 /* 235 * Iterate over all cachefiles for the pool, past or present. When the 236 * cachefile is changed, the new one is pushed onto this list, allowing 237 * us to update previous cachefiles that no longer contain this pool. 238 */ 239 ccw_failure = B_FALSE; 240 for (dp = list_head(&target->spa_config_list); dp != NULL; 241 dp = list_next(&target->spa_config_list, dp)) { 242 spa_t *spa = NULL; 243 if (dp->scd_path == NULL) 244 continue; 245 246 /* 247 * Iterate over all pools, adding any matching pools to 'nvl'. 248 */ 249 nvl = NULL; 250 while ((spa = spa_next(spa)) != NULL) { 251 nvlist_t *nvroot = NULL; 252 /* 253 * Skip over our own pool if we're about to remove 254 * ourselves from the spa namespace or any pool that 255 * is readonly. Since we cannot guarantee that a 256 * readonly pool would successfully import upon reboot, 257 * we don't allow them to be written to the cache file. 258 */ 259 if ((spa == target && removing) || 260 (spa_state(spa) == POOL_STATE_ACTIVE && 261 !spa_writeable(spa))) 262 continue; 263 264 mutex_enter(&spa->spa_props_lock); 265 tdp = list_head(&spa->spa_config_list); 266 if (spa->spa_config == NULL || 267 tdp->scd_path == NULL || 268 strcmp(tdp->scd_path, dp->scd_path) != 0) { 269 mutex_exit(&spa->spa_props_lock); 270 continue; 271 } 272 273 if (nvl == NULL) 274 nvl = fnvlist_alloc(); 275 276 fnvlist_add_nvlist(nvl, spa->spa_name, 277 spa->spa_config); 278 mutex_exit(&spa->spa_props_lock); 279 280 if (nvlist_lookup_nvlist(nvl, spa->spa_name, &nvroot) == 0) 281 spa_config_clean(nvroot); 282 } 283 284 error = spa_config_write(dp, nvl); 285 if (error != 0) 286 ccw_failure = B_TRUE; 287 nvlist_free(nvl); 288 } 289 290 if (ccw_failure) { 291 /* 292 * Keep trying so that configuration data is 293 * written if/when any temporary filesystem 294 * resource issues are resolved. 295 */ 296 if (target->spa_ccw_fail_time == 0) { 297 zfs_ereport_post(FM_EREPORT_ZFS_CONFIG_CACHE_WRITE, 298 target, NULL, NULL, 0, 0); 299 } 300 target->spa_ccw_fail_time = gethrtime(); 301 spa_async_request(target, SPA_ASYNC_CONFIG_UPDATE); 302 } else { 303 /* 304 * Do not rate limit future attempts to update 305 * the config cache. 306 */ 307 target->spa_ccw_fail_time = 0; 308 } 309 310 /* 311 * Remove any config entries older than the current one. 312 */ 313 dp = list_head(&target->spa_config_list); 314 while ((tdp = list_next(&target->spa_config_list, dp)) != NULL) { 315 list_remove(&target->spa_config_list, tdp); 316 if (tdp->scd_path != NULL) 317 spa_strfree(tdp->scd_path); 318 kmem_free(tdp, sizeof (spa_config_dirent_t)); 319 } 320 321 spa_config_generation++; 322 323 if (postsysevent) 324 spa_event_notify(target, NULL, ESC_ZFS_CONFIG_SYNC); 325} 326 327/* 328 * Sigh. Inside a local zone, we don't have access to /etc/zfs/zpool.cache, 329 * and we don't want to allow the local zone to see all the pools anyway. 330 * So we have to invent the ZFS_IOC_CONFIG ioctl to grab the configuration 331 * information for all pool visible within the zone. 332 */ 333nvlist_t * 334spa_all_configs(uint64_t *generation) 335{ 336 nvlist_t *pools; 337 spa_t *spa = NULL; 338 339 if (*generation == spa_config_generation) 340 return (NULL); 341 342 pools = fnvlist_alloc(); 343 344 mutex_enter(&spa_namespace_lock); 345 while ((spa = spa_next(spa)) != NULL) { 346 if (INGLOBALZONE(curthread) || 347 zone_dataset_visible(spa_name(spa), NULL)) { 348 mutex_enter(&spa->spa_props_lock); 349 fnvlist_add_nvlist(pools, spa_name(spa), 350 spa->spa_config); 351 mutex_exit(&spa->spa_props_lock); 352 } 353 } 354 *generation = spa_config_generation; 355 mutex_exit(&spa_namespace_lock); 356 357 return (pools); 358} 359 360void 361spa_config_set(spa_t *spa, nvlist_t *config) 362{ 363 mutex_enter(&spa->spa_props_lock); 364 nvlist_free(spa->spa_config); 365 spa->spa_config = config; 366 mutex_exit(&spa->spa_props_lock); 367} 368 369/* 370 * Generate the pool's configuration based on the current in-core state. 371 * 372 * We infer whether to generate a complete config or just one top-level config 373 * based on whether vd is the root vdev. 374 */ 375nvlist_t * 376spa_config_generate(spa_t *spa, vdev_t *vd, uint64_t txg, int getstats) 377{ 378 nvlist_t *config, *nvroot; 379 vdev_t *rvd = spa->spa_root_vdev; 380 unsigned long hostid = 0; 381 boolean_t locked = B_FALSE; 382 uint64_t split_guid; 383 384 if (vd == NULL) { 385 vd = rvd; 386 locked = B_TRUE; 387 spa_config_enter(spa, SCL_CONFIG | SCL_STATE, FTAG, RW_READER); 388 } 389 390 ASSERT(spa_config_held(spa, SCL_CONFIG | SCL_STATE, RW_READER) == 391 (SCL_CONFIG | SCL_STATE)); 392 393 /* 394 * If txg is -1, report the current value of spa->spa_config_txg. 395 */ 396 if (txg == -1ULL) 397 txg = spa->spa_config_txg; 398 399 config = fnvlist_alloc(); 400 401 fnvlist_add_uint64(config, ZPOOL_CONFIG_VERSION, spa_version(spa)); 402 fnvlist_add_string(config, ZPOOL_CONFIG_POOL_NAME, spa_name(spa)); 403 fnvlist_add_uint64(config, ZPOOL_CONFIG_POOL_STATE, spa_state(spa)); 404 fnvlist_add_uint64(config, ZPOOL_CONFIG_POOL_TXG, txg); 405 fnvlist_add_uint64(config, ZPOOL_CONFIG_POOL_GUID, spa_guid(spa)); 406 if (spa->spa_comment != NULL) { 407 fnvlist_add_string(config, ZPOOL_CONFIG_COMMENT, 408 spa->spa_comment); 409 } 410 411#ifdef _KERNEL 412 hostid = zone_get_hostid(NULL); 413#else /* _KERNEL */ 414 /* 415 * We're emulating the system's hostid in userland, so we can't use 416 * zone_get_hostid(). 417 */ 418 (void) ddi_strtoul(hw_serial, NULL, 10, &hostid); 419#endif /* _KERNEL */ 420 if (hostid != 0) { 421 fnvlist_add_uint64(config, ZPOOL_CONFIG_HOSTID, hostid); 422 } 423 fnvlist_add_string(config, ZPOOL_CONFIG_HOSTNAME, utsname.nodename); 424 425 int config_gen_flags = 0; 426 if (vd != rvd) { 427 fnvlist_add_uint64(config, ZPOOL_CONFIG_TOP_GUID, 428 vd->vdev_top->vdev_guid); 429 fnvlist_add_uint64(config, ZPOOL_CONFIG_GUID, 430 vd->vdev_guid); 431 if (vd->vdev_isspare) { 432 fnvlist_add_uint64(config, 433 ZPOOL_CONFIG_IS_SPARE, 1ULL); 434 } 435 if (vd->vdev_islog) { 436 fnvlist_add_uint64(config, 437 ZPOOL_CONFIG_IS_LOG, 1ULL); 438 } 439 vd = vd->vdev_top; /* label contains top config */ 440 } else { 441 /* 442 * Only add the (potentially large) split information 443 * in the mos config, and not in the vdev labels 444 */ 445 if (spa->spa_config_splitting != NULL) 446 fnvlist_add_nvlist(config, ZPOOL_CONFIG_SPLIT, 447 spa->spa_config_splitting); 448 fnvlist_add_boolean(config, 449 ZPOOL_CONFIG_HAS_PER_VDEV_ZAPS); 450 451 config_gen_flags |= VDEV_CONFIG_MOS; 452 } 453 454 /* 455 * Add the top-level config. We even add this on pools which 456 * don't support holes in the namespace. 457 */ 458 vdev_top_config_generate(spa, config); 459 460 /* 461 * If we're splitting, record the original pool's guid. 462 */ 463 if (spa->spa_config_splitting != NULL && 464 nvlist_lookup_uint64(spa->spa_config_splitting, 465 ZPOOL_CONFIG_SPLIT_GUID, &split_guid) == 0) { 466 fnvlist_add_uint64(config, ZPOOL_CONFIG_SPLIT_GUID, 467 split_guid); 468 } 469 470 nvroot = vdev_config_generate(spa, vd, getstats, config_gen_flags); 471 fnvlist_add_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, nvroot); 472 nvlist_free(nvroot); 473 474 /* 475 * Store what's necessary for reading the MOS in the label. 476 */ 477 fnvlist_add_nvlist(config, ZPOOL_CONFIG_FEATURES_FOR_READ, 478 spa->spa_label_features); 479 480 if (getstats && spa_load_state(spa) == SPA_LOAD_NONE) { 481 ddt_histogram_t *ddh; 482 ddt_stat_t *dds; 483 ddt_object_t *ddo; 484 485 ddh = kmem_zalloc(sizeof (ddt_histogram_t), KM_SLEEP); 486 ddt_get_dedup_histogram(spa, ddh); 487 fnvlist_add_uint64_array(config, 488 ZPOOL_CONFIG_DDT_HISTOGRAM, 489 (uint64_t *)ddh, sizeof (*ddh) / sizeof (uint64_t)); 490 kmem_free(ddh, sizeof (ddt_histogram_t)); 491 492 ddo = kmem_zalloc(sizeof (ddt_object_t), KM_SLEEP); 493 ddt_get_dedup_object_stats(spa, ddo); 494 fnvlist_add_uint64_array(config, 495 ZPOOL_CONFIG_DDT_OBJ_STATS, 496 (uint64_t *)ddo, sizeof (*ddo) / sizeof (uint64_t)); 497 kmem_free(ddo, sizeof (ddt_object_t)); 498 499 dds = kmem_zalloc(sizeof (ddt_stat_t), KM_SLEEP); 500 ddt_get_dedup_stats(spa, dds); 501 fnvlist_add_uint64_array(config, 502 ZPOOL_CONFIG_DDT_STATS, 503 (uint64_t *)dds, sizeof (*dds) / sizeof (uint64_t)); 504 kmem_free(dds, sizeof (ddt_stat_t)); 505 } 506 507 if (locked) 508 spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG); 509 510 return (config); 511} 512 513/* 514 * Update all disk labels, generate a fresh config based on the current 515 * in-core state, and sync the global config cache (do not sync the config 516 * cache if this is a booting rootpool). 517 */ 518void 519spa_config_update(spa_t *spa, int what) 520{ 521 vdev_t *rvd = spa->spa_root_vdev; 522 uint64_t txg; 523 int c; 524 525 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 526 527 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER); 528 txg = spa_last_synced_txg(spa) + 1; 529 if (what == SPA_CONFIG_UPDATE_POOL) { 530 vdev_config_dirty(rvd); 531 } else { 532 /* 533 * If we have top-level vdevs that were added but have 534 * not yet been prepared for allocation, do that now. 535 * (It's safe now because the config cache is up to date, 536 * so it will be able to translate the new DVAs.) 537 * See comments in spa_vdev_add() for full details. 538 */ 539 for (c = 0; c < rvd->vdev_children; c++) { 540 vdev_t *tvd = rvd->vdev_child[c]; 541 if (tvd->vdev_ms_array == 0) { 542 vdev_ashift_optimize(tvd); 543 vdev_metaslab_set_size(tvd); 544 } 545 vdev_expand(tvd, txg); 546 } 547 } 548 spa_config_exit(spa, SCL_ALL, FTAG); 549 550 /* 551 * Wait for the mosconfig to be regenerated and synced. 552 */ 553 txg_wait_synced(spa->spa_dsl_pool, txg); 554 555 /* 556 * Update the global config cache to reflect the new mosconfig. 557 */ 558 spa_config_sync(spa, B_FALSE, what != SPA_CONFIG_UPDATE_POOL); 559 560 if (what == SPA_CONFIG_UPDATE_POOL) 561 spa_config_update(spa, SPA_CONFIG_UPDATE_VDEVS); 562} 563